Hypoglycemia can be caused by many different things including liver failure, sepsis, Addison’s disease, and overdose of insulin in the treatment of diabetes mellitus. A tumor of the pancreas called an insulinoma can also cause low blood glucose due to excessive production of insulin. After detecting hypoglycemia on a blood sample, determining the cause includes a full history, physical exam, CBC, biochemistry profile, and urinalysis. More advanced testing such as imaging, biopsy, or ACTH stimulation testing may be recommended.